Hahaha when I saw the title of your post, I was like "Can I really call an amount of how much POB I would need not to have issues anymore?" I doubt that so much.
I prefer live my life with plans on making tomorrow better than my yesterday and today. So I'll try to make as much POB as I could without stressing on it too much.
Make money while you can, rest while you can and try to live life simple... You might just not have an issue
Is good advice!